FR: Add user centric dashboard filtering

[MushuEE]

What I would like
The ability to filter a dashboard to only advertise issues/PRs that I am involved with as either a reviewer, assignee, creator etc. This would enable the k8s/test-infra project to migrate from the Gubernator PR Dashboard to Triage Party and most likely deprecate the rest of the that service.

What is needed
OAuth with GitHub needs to be added so Triage Party has some understanding of what user is active and interested. Gubernator login can be used as reference.

FE changes to allow users to specify their ID and a way to tell TriageParty they are only interested in their own issues.

[MushuEE]

@tstromberg I started playing around with this and was able to get oauth2 working for token auth. But I am wondering if this would be just as easy with proper filtering for a specific user?

[tstromberg]

@MushuEE - I think there is a lot of value in having a page which is centered around the current user. For instance, which PR's or issues they haven't followed up on.